Array frame design for electrified vehicle battery arrays

ABSTRACT

A battery array frame according to an exemplary aspect of the present disclosure includes, among other things, a frame body, and a thermal fin including a body embedded in the frame body and a leg that extends outside of the frame body. The thermal fin is flexible between a first position in which the leg is spaced farther from a surface of the frame body and a second position in which the leg is spaced closer to the surface of the frame body.

TECHNICAL FIELD

This disclosure relates to a battery array for an electrified vehicle.The battery array includes unique array frame designs for housingbattery cells of the battery array.

BACKGROUND

Electrified vehicles, such as hybrid electric vehicles (HEV's), plug-inhybrid electric vehicles (PHEV's), battery electric vehicles (BEV's), orfuel cell vehicles differ from conventional motor vehicles because theyare powered by electric machines (i.e., electric motors and/orgenerators) instead of or in addition to an internal combustion engine.High voltage current for powering these types of electric machines istypically supplied by a high voltage battery assembly.

Electrified vehicle battery assemblies typically include multiplebattery arrays. Each battery array includes a plurality of batterycells. The battery cells must be secured relative to one another. Thebattery array must also be secured to arrest movement once mountedwithin the battery assembly.

SUMMARY

A battery array frame according to an exemplary aspect of the presentdisclosure includes, among other things, a frame body, and a thermal finincluding a body embedded in the frame body and a leg that extendsoutside of the frame body. The thermal fin is flexible between a firstposition in which the leg is spaced farther from a surface of the framebody and a second position in which the leg is spaced closer to thesurface of the frame body.

In a further non-limiting embodiment of the foregoing battery arrayframe, a battery cell is housed within a pocket on at least one side ofthe frame body.

In a further non-limiting embodiment of either of the foregoing batteryarray frames, the thermal fin is segmented into a plurality of legportions by notches or cuts.

In a further non-limiting embodiment of any of the foregoing batteryarray frames, the frame body is a unitary plastic structure, and thebody is molded or inserted into the structure.

In a further non-limiting embodiment of any of the foregoing batteryarray frames, the leg extends transversely from the body.

In a further non-limiting embodiment of any of the foregoing batteryarray frames, the leg extends at an obtuse angle relative to the body inthe first position.

In a further non-limiting embodiment of any of the foregoing batteryarray frames, the leg is perpendicular to the body in the secondposition.

In a further non-limiting embodiment of any of the foregoing batteryarray frames, the leg includes a bent end portion.

In a further non-limiting embodiment of any of the foregoing batteryarray frames, the bent end portion is received within a relief notch inthe second position.

In a further non-limiting embodiment of any of the foregoing batteryarray frames, one end of the body is received in a groove of a topsurface of the frame body, an opposite end extends through a passage ofa bottom surface of the frame body, and the leg extends beneath thebottom surface.

A battery array according to another exemplary aspect of the presentdisclosure includes, among other things, a first array frame thatincludes a thermal fin and a second array frame connected to the firstarray frame, the second array frame including a relief notch thatreceives a portion of the thermal fin.

In a further non-limiting embodiment of the foregoing battery array, therelief notch is formed in a bottom surface of the second array frame.

In a further non-limiting embodiment of either of the foregoing batteryarrays, the thermal fin includes a body positioned within a frame bodyof the first array frame and a leg that extends outside of the framebody.

In a further non-limiting embodiment of any of the foregoing batteryarrays, the leg includes a bent end portion that is received within therelief notch.

In a further non-limiting embodiment of any of the foregoing batteryarrays, the thermal fin is segmented into a plurality of leg portions bynotches or cuts.

A method according to another exemplary aspect of the present disclosureincludes, among other things, positioning an array frame relative to acooling plate of a battery array. The array frame including a thermalfin located in a first position during the positioning step. Anadditional method step includes flexing the thermal fin to a second,different position in response to contacting the cooling plate.

In a further non-limiting embodiment of the foregoing method, theflexing step includes tucking a bent end portion of a leg of the thermalfin into a relief notch of an adjacent array frame.

In a further non-limiting embodiment of either of the foregoing methods,the method includes connecting the array frame to a second array frameprior to the positioning step.

In a further non-limiting embodiment of any of the foregoing methods,the thermal fin includes a body and a leg, and the leg is movablebetween the first position in which it extends at an obtuse anglerelative to the body and the second position in which it isperpendicular to the body.

In a further non-limiting embodiment of any of the foregoing methods,the method includes dissipating heat from a battery cell, into thethermal fin, and then into the cooling plate or adding heat from thecooling plate, into the thermal fin, and then into the battery cell.

The embodiments, examples and alternatives of the preceding paragraphs,the claims, or the following description and drawings, including any oftheir various aspects or respective individual features, may be takenindependently or in any combination. Features described in connectionwith one embodiment are applicable to all embodiments, unless suchfeatures are incompatible.

The various features and advantages of this disclosure will becomeapparent to those skilled in the art from the following detaileddescription. The drawings that accompany the detailed description can bebriefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates a powertrain of an electrified vehicle.

FIGS. 2A and 2B illustrate an array frame according to a firstembodiment of this disclosure.

FIGS. 3A and 3B illustrate the stacking of multiple array frames tobuild a battery array.

FIG. 3C is a blown-up view of encircled area AR1 of FIG. 3B.

FIG. 3D illustrates a battery array end plate connectable to an arrayframe.

FIGS. 4A and 4B illustrate recessed grooves of additional array frames.

FIG. 5 illustrates a battery array built using multiple array frames.

FIGS. 6A, 6B and 6C illustrate lifting arms of additional array frames.

FIGS. 7A, 7B, 7C, 7D and 7E illustrate exemplary thermal fin designs ofan array frame according to another embodiment of this disclosure.

FIG. 8 illustrates a battery pack according to an embodiment of thisdisclosure.

FIG. 9 is a blown-up view of encircled area AR2 of FIG. 8.

FIGS. 10A, 10B and 10C illustrate an installation procedure of a batteryarray having the features of FIGS. 8 and 9.

FIG. 10D illustrates another battery pack installation procedure.

FIG. 11 illustrates a retention clip assembly according to an embodimentof this disclosure.

FIG. 12 illustrates a cross-sectional view of a battery pack thatutilizes the retention clip assembly of FIG. 11.

DETAILED DESCRIPTION

This disclosure describes a battery array of an electrified vehicle. Aplurality of array frames may be stacked and connected to one another tobuild the battery array. The array frames may include multiple designfeatures for connecting adjacent array frames together. For example, thearray frames may include retention features such as rigid and flexiblesnap arms that engage snap arms of adjacent array frames to build thebattery array. The array frames may additionally include recessedgrooves that accommodate tension straps, and lifting arms that establishtool engagement areas for lifting and handling the battery arrays. Theseand other features are discussed in greater detail in the paragraphsthat follow.

FIG. 1 schematically illustrates a powertrain 10 for an electrifiedvehicle 12. Although depicted as a HEV, it should be understood that theconcepts described herein are not limited to HEV's and could extend toother electrified vehicles, including, but not limited to, PHEV's andBEV's.

In one embodiment, the powertrain 10 is a power-split powertrain systemthat employs a first drive system and a second drive system. The firstdrive system includes a combination of an engine 14 and a generator 18(i.e., a first electric machine). The second drive system includes atleast a motor 22 (i.e., a second electric machine), the generator 18,and a battery assembly 24. In this example, the second drive system isconsidered an electric drive system of the powertrain 10. The first andsecond drive systems generate torque to drive one or more sets ofvehicle drive wheels 28 of the electrified vehicle 12.

The engine 14, such as an internal combustion engine, and the generator18 may be connected through a power transfer unit 30, such as aplanetary gear set. Of course, other types of power transfer units,including other gear sets and transmissions, may be used to connect theengine 14 to the generator 18. In one non-limiting embodiment, the powertransfer unit 30 is a planetary gear set that includes a ring gear 32, asun gear 34, and a carrier assembly 36.

The generator 18 can be driven by the engine 14 through the powertransfer unit 30 to convert kinetic energy to electrical energy. Thegenerator 18 can alternatively function as a motor to convert electricalenergy into kinetic energy, thereby outputting torque to a shaft 38connected to the power transfer unit 30. Because the generator 18 isoperatively connected to the engine 14, the speed of the engine 14 canbe controlled by the generator 18.

The ring gear 32 of the power transfer unit 30 may be connected to ashaft 40, which is connected to vehicle drive wheels 28 through a secondpower transfer unit 44. The second power transfer unit 44 may include agear set having a plurality of gears 46. Other power transfer units mayalso be suitable. The gears 46 transfer torque from the engine 14 to adifferential 48 to ultimately provide traction to the vehicle drivewheels 28. The differential 48 may include a plurality of gears thatenable the transfer of torque to the vehicle drive wheels 28. In oneembodiment, the second power transfer unit 44 is mechanically coupled toan axle 50 through the differential 48 to distribute torque to thevehicle drive wheels 28.

The motor 22 can also be employed to drive the vehicle drive wheels 28by outputting torque to a shaft 52 that is also connected to the secondpower transfer unit 44. In one embodiment, the motor 22 and thegenerator 18 cooperate as part of a regenerative braking system in whichboth the motor 22 and the generator 18 can be employed as motors tooutput torque. For example, the motor 22 and the generator 18 can eachoutput electrical power to the battery assembly 24.

The battery assembly 24 is an example type of electrified vehiclebattery assembly. The battery assembly 24 may include a high voltagebattery pack that includes a plurality of battery arrays capable ofoutputting electrical power to operate the motor 22 and the generator18. Other types of energy storage devices and/or output devices can alsobe used to electrically power the electrified vehicle 12.

In one non-limiting embodiment, the electrified vehicle 12 has two basicoperating modes. The electrified vehicle 12 may operate in an ElectricVehicle (EV) mode where the motor 22 is used (generally withoutassistance from the engine 14) for vehicle propulsion, thereby depletingthe battery assembly 24 state of charge up to its maximum allowabledischarging rate under certain driving patterns/cycles. The EV mode isan example of a charge depleting mode of operation for the electrifiedvehicle 12. During EV mode, the state of charge of the battery assembly24 may increase in some circumstances, for example due to a period ofregenerative braking. The engine 14 is generally OFF under a default EVmode but could be operated as necessary based on a vehicle system stateor as permitted by the operator.

The electrified vehicle 12 may additionally be operated in a Hybrid(HEV) mode in which the engine 14 and the motor 22 are both used forvehicle propulsion. The HEV mode is an example of a charge sustainingmode of operation for the electrified vehicle 12. During the HEV mode,the electrified vehicle 12 may reduce the motor 22 propulsion usage inorder to maintain the state of charge of the battery assembly 24 at aconstant or approximately constant level by increasing the engine 14propulsion usage. The electrified vehicle 12 may be operated in otheroperating modes in addition to the EV and HEV modes within the scope ofthis disclosure.

FIGS. 2A and 2B illustrate an array frame 54 that houses at least twobattery cells 56. A plurality of array frames 54 may be stackedside-by-side to build a battery array (see, e.g., battery array 78 ofFIGS. 3A, 3B and 3C). One or more battery arrays that include multiplearray frames 54 and battery cells 56 can be assembled and mounted insidea battery pack that is employed by a battery assembly, such as thebattery assembly 24 of the electrified vehicle 12 of FIG. 1, toelectrically power an electrified vehicle.

In one embodiment, the battery cells 56 are pouch cells for a highvoltage battery assembly. One non-limiting example of a suitable pouchbattery cell is a lithium-ion polymer battery. However, other types ofbattery cells are also contemplated.

The array frame 54 includes a frame body 58 that extends along alongitudinal axis A (see FIG. 2A). The frame body 58 includes a topsurface 60, a bottom surface 62 and frame arms 64 that connect betweenthe top surface 60 and the bottom surface 62. In one embodiment, the topsurface 60 and the bottom surface 62 extend in parallel with thelongitudinal axis A, and the frame arms 64 are transverse to thelongitudinal axis A. In another embodiment, the frame body 58 is aunitary, plastic structure.

A thermal fin 66 may be partially embedded within the frame body 58 andextend between the top surface 60 and the bottom surface 62. In oneembodiment, the thermal fin 66 is an aluminum thermal fin. However,other materials are additionally contemplated. The thermal fin 66separates the battery cells 56 and may be in contact with side faces 55of the battery cells 56. During certain conditions, the thermal fin 66removes heat from the battery cells 56. In other conditions, the thermalfin 66 adds heat to the battery cells 56. The frame body 58 establishespockets 76 on both sides of the thermal fin 66. The battery cells 56 maybe received within the pockets 76 to house the battery cells 56 withinthe array frame 54.

In one embodiment, the thermal fin 66 includes a body 74 and a leg 72that extends from the body 74. The body 74 may be embedded or moldedinto the frame body 58, while the leg 72 extends outside of the framebody 58. In another embodiment, the thermal fin 66 may be inserted intothe frame body 58 such that one end of the body 74 is located within agroove 68 formed in the top surface 60 of the frame body 58, and anopposite end of the body 74 may extend through a passage 70 formedthrough the bottom surface 62 of the frame body 58. The leg 72 of thethermal fin 66 may be oriented transversely to the body 74 so it extendsunderneath the bottom surface 62 to the position outside of the framebody 58. The leg 72 may contact a cooling plate or a thermal interfacematerial (not shown in FIGS. 2A, 2B) to dissipate any heat absorbed fromthe battery cells 56. In one embodiment, the leg 72 extends to aposition that is beyond the side face 55 of the battery cell 56 housedsubstantially above the leg 72.

The frame body 58 may include a plurality of retention features 80 thatare integrated into the top surface 60. The bottom surface 62 maysimilarly include a plurality of integrated retention features 88. Theretention features 80, 88 may engage corresponding retention features ofadjacent array frames to build a battery array, as discussed in greaterdetail below. In yet another embodiment, the frame arms 64 may includeretention features similar to the retention features 80, 88.

Referring to FIGS. 3A, 3B and 3C, a plurality of array frames 54 may bestacked side-by-side to construct a battery array 78. The battery array78 includes a plurality of array frames 54 that house a plurality ofbattery cells 56. Two array frames 54 are depicted in FIG. 3A, whichomits the battery cells for clarity, and a plurality of array frames 54including the battery cells 56 are depicted in FIGS. 3B and 3C. Thisdisclosure is not limited to a specific number of array frames 54 and/orbattery cells 56 and is not intended to be limited to the specificconfigurations shown by these Figures.

In one embodiment, the top surface 60 of the frame body 58 of the arrayframe 54 is rotationally symmetric about a vertical axis V that istransverse to the longitudinal axis A. In another embodiment, the bottomsurface 62 is rotationally symmetric about the vertical axis V. In yetanother embodiment, both the top surface 60 and the bottom surface 62are rotationally symmetric about the vertical axis V. In this way, thearray frames 54 can be provided in a repeating fashion to construct thebattery array 78. The symmetry of the top surface 60 and/or the bottomsurface 62 permits the use of common array end plates, thereby reducingcost and complexity of the battery array 78. In other words, unique lefthand and right hand array end plates are not required to construct thebattery array 78. In another embodiment, the battery array 78 mayinclude an end plate 79 that is connectable to the array frame 54 (seeFIG. 3D).

The top surface 60 of the frame body 58 includes a first side 84 and asecond side 86 that both extend between opposing ends 96, 98 (see FIG.3A). The first side 84 and the second side 86 both include a pluralityof retention features 80 for connecting the array frame 54 to anadjacent array frame 54. In one embodiment, the retention features 80protrude from both the first side 84 and the second side 86 of the topsurface 60. In one embodiment, the top surface 60 of each array frame 54is substantially flat.

In another non-limiting embodiment, the retention features 80 of the topsurface 60 include a plurality of rigid snap arms 82A and a plurality offlexible snap arms 82B oriented in an alternating pattern along each ofthe first side 84 and the second side 86 of the top surface 60. Becausethe top surface 60 is rotationally symmetric about the vertical axis V,each flexible snap arm 82B of the first and second sides 84, 86 arealigned directly across the top surface 60 from a rigid snap arm 82A onthe opposite side 84, 86. Thus, the array frames 54 provide a repeatingdesign that simplifies assembly and reduces complexity of the batteryarray 78.

The rigid snap arms 82A and the flexible snap arms 82B of both the firstside 84 and the second side 86 are oriented to engage correspondingfeatures of an adjacent array frame 54 to connect the array frames 54together. For example, as best illustrated in FIGS. 3B and 3C, theflexible snap arms 82B may be received over top of the rigid snap arms82A to connect adjacent array frames 54. The flexible snap arms 82B mayflex slightly in a direction F as the rigid snap arms 82A are pushedtoward the flexible snap arms 82B. In one embodiment, the rigid snaparms 82A and the flexible snap arms 82B each include nubs 85 that snaptogether in an abutting fashion to connect adjacent array frames 54together. The nubs 85 may be slightly ramped in order to create enoughforce during contact to move the flexible snaps arms 82B in thedirection F and allow the rigid snap arms 82A to pass into a groove 59located under the flexible snap arms 82.

In another embodiment, the flexible snap arms 82B extend in a plane P1and the rigid snap arms 82A extend in a different plane P2. The plane P1is offset from the plane P2, and in some embodiments is locatedvertically above the plane P2 to provide an engagement area for thesefeatures to snap together. In addition, because the flexible snap arms82B are exposed at a location that is external to the rigid snap arms82A, the array frames 54 can be accessed and disassembled if necessary.

The top surface 60 of each array frame 54 may additionally include oneor more recessed grooves 92 (see FIG. 3A). In one embodiment, eachrecessed groove 92 extends between the first side 84 and the second side86 of the top surface 60 and is disposed between a rigid snap arm 82Aand a flexible snap arm 82B on the first side 84 and the second side 86.The recessed grooves 92 of adjacent array frames 54 align with oneanother to accommodate tension straps 94 (see FIG. 5). The tensionstraps 94 bind the battery array 78 in a lengthwise direction tomaintain a consistent array length and resist bulging of the batterycells 56 during certain conditions. The recessed grooves 92 seat thetension straps 94 flush with the top surfaces 60 of the array frames 54to avoid interfering with additional arrays that may be stacked on topof the battery array 78.

In one non-limiting embodiment, the tension straps 94 include detents 57(see FIGS. 4A and 5) that are stamped into the tension straps 94. Thedetents 57 may extend toward either the top surface 60 or the bottomsurface 62 of the array frames 54. The detents 57 may reduce rattle ofthe tension straps 94.

In another embodiment, the bottom surfaces 62 of the array frames 54include a plurality of retention features 88. Similar to the retentionfeatures 80 of the top surface 60, the retention features 88 may includeboth rigid snap arms 89A and flexible snap arms 89B. The flexible snaparms 89B are located outside of, which in this embodiment is beneath,the rigid snap arms 89A so they are accessible to disassemble the arrayframes 54. In one non-limiting embodiment, the rigid snaps arms 89A aredisposed directly across the bottom surface 62 from a flexible snap arm89B. In another embodiment, the retention features 88 are provided onlyat the outside edges, such as within the outer quarters of the bottomsurface 62 (see FIG. 3A).

In another embodiment, as shown in FIGS. 4A and 4B, the bottom surface62 of each array frame 54 can be equipped with one or more recessedgrooves 92. The recessed grooves 92 may accommodate additional tensionstraps 94 that extend along a bottom of the battery array 78. In oneembodiment, the recessed grooves 92 of the bottom surfaces 62 of thearray frames 54 are positioned outboard of the thermal fins 66 and arepositioned between the thermal fin 66 and a foot 19 of the bottomsurface 62 (see FIG. 4A). In another embodiment, the recessed grooves 92and tension straps 94 are positioned between opposing feet 19 of thebottom surface 62 of the array frame 54 (see FIG. 4B). A center of thebottom surface 62 may be elevated relative to the feet 19.

FIG. 6A illustrates additional features of an array frame 54. In oneembodiment, the top surface 60 of the frame body 58 of the array frame54 includes opposing ends 96, 98. The first side 84 and the second side86 (only the first side 84 is shown in the side view of FIG. 6A) connectbetween the opposing ends 96, 98.

In this embodiment, each of the opposing ends 96, 98 includes a liftingarm 91. The lifting arms 91 are disposed along the longitudinal axis A.In one embodiment, the lifting arms 91 extend outboard of, or laterallybeyond, the frame arms 64 of the frame body 58. In other words, thelifting arms 91 jut outwardly from the array frame 54 beyond a peripheryestablished by the frame arms 64. In another embodiment, the liftingarms 91 extend upwardly from the top surface 60 of the array frame 58(see FIG. 6B).

Each lifting arm 91 may include a lip 93 and a recess 95. In oneembodiment, the recess 95 is directly inboard of the lip 93. The recess95 of each lifting arm 91 establishes an engagement area 97 for liftingand handling a battery array 78 that is constructed of a plurality ofthe array frames 54. Alternatively, the lifting arm 91 may eliminate therecess 95 and provide a substantially flat engagement area 97 (see FIG.6C).

A lifting tool 99 may engage the engagement area 97 on each of theopposing ends 96, 98 of the array frame 54. For example, in onenon-limiting embodiment, the recesses 95 of the lifting arms 91 ofadjacent array frames 54 align to establish a uniform engagement area 97for lifting and handling a battery array 78 (see, e.g., FIG. 5). Inother words, the connected array frames 54 can be lifted as asingle-unit using the lifting arms 91.

FIGS. 7A and 7B illustrate a battery array 178 according to anotherembodiment of this disclosure. In this disclosure, like referencenumbers designate like elements where appropriate and reference numeralswith the addition of 100 or multiples thereof designate modifiedelements that are understood to incorporate the same features andbenefits of the corresponding original elements.

The battery array 178 of this embodiment is constructed of multiplearray frames 154 that house battery cells 156. The array frames 154 arepositioned side-by-side and can be connected to one another to build thebattery array 178. Each array frame 154 includes a thermal fin 166 thatis molded into or otherwise embedded within the array frame 154. Thethermal fins 166 separate the battery cells 156 housed by each arrayframe 154.

In one embodiment, each thermal fin 166 includes a body 174 and a leg172 that extends from the body 174. The leg 172 may be transverse to thebody 174 so that it extends along an underside of the array frame 154 toa position outside of the array frame 154. In other words, unlike thebody 174, the leg 172 is not encased or embedded within the array frame154.

In one embodiment, the leg 172 of each thermal fin 166 is flexiblebetween a first position P (see FIG. 7A) and a second position P′ (seeFIG. 7B) to promote improved contact with a cooling plate 165 of thebattery array 178. The battery array 178 may rest on top of the coolingplate 165 when assembled. The legs 172 of each thermal fin 166 maycontact the cooling plate 165 (or a thermal interface material) todissipate any heat absorbed from the battery cells 156 or to heat up thebattery cells 156.

In the first position P, the leg 172 of each thermal fin 166 may extendat an obtuse angle a relative to the body 174. Therefore, the leg 172can flex to the second position P′ as the battery array 178 is movedinto position atop the cooling plate 165. In the second position P′, theleg 172 of each thermal fin 166 may be substantially perpendicular tothe body 174.

In another embodiment, the leg 172 of each thermal fin 166 additionallyincludes a bent end portion 167. Each bent end portion 167 may be tuckedinto a relief notch 169 formed in a surface 101 of an adjacent arrayframe 154 when the leg 172 is moved to the second position P′. Thishelps avoid damaging a thermal interface material that may be located onthe cooling plate 165. In this embodiment, the surface 101 is a bottomsurface of the adjacent array frame 154. Therefore, the battery array178 may be stacked on the cooling plate 165 without the thermal fins 166interfering with the stacking. In yet another embodiment, the leg 172 ofeach thermal fin 166 is spaced from the surface 101 in the firstposition P and abuts the surface 101 in the second position P′.

In another embodiment, shown in the top view of FIG. 7C, the thermal fin166 includes a first leg 172A and a second leg 172B that extend from abody 174. In one embodiment, the first leg 172A and the second leg 172Bextend in opposite directions from the body 174 such that the thermalfin 166 is rotationally symmetric. A rotationally symmetric thermal fin166 may allow for a shorter cold plate design when used in conjunctionwith a rotationally symmetric array frame 154.

FIGS. 7D and 7E illustrate segmented thermal fins 266, 366,respectively. In the embodiment of FIG. 7D, the thermal fin 266 is asegmented thermal fin that includes a body 274 and a leg 272 thatextends transversely from the body 274. One or more notches 273 may beformed in the leg 272 to provide multiple leg portions 272L. The notches273 may accommodate tension straps 94, in one non-limiting embodiment.

In the additional embodiment of FIG. 7E, the thermal fin 366 may includea body 374 and a leg 372 that extends transversely from the body 374.One or more cuts 375 may extend into the leg 372 to form multiple legportions 372L. The cuts 375 segment the thermal fin 366 to allow eachleg portion 372L to position itself independently of the other legportions 372L, thereby promoting improved contact with a coolinginterface (e.g., a tray or cold plate). In other words, the leg portions372L can provide improved heat transfer by better conforming to theshape of a cold plate.

FIGS. 8 and 9 illustrate a battery pack 200 that includes at least onebattery array 278. The battery array 278 may include one or more of thefeatures described above with respect to FIGS. 2-7. In one non-limitingembodiment, the battery array 278 includes array frames 254 that housebattery cells 256. The array frames 254 each include a top surface 260,a bottom surface 262 and frame arms 264 that connect between the topsurface 260 and the bottom surface 262.

The battery array 278 is positioned on a tray 201 of the battery pack200. A cooling plate 265 may be positioned between the tray 201 and thebottom surface 262 of each array frame 254, in one embodiment. Inanother non-limiting embodiment, an extension 225 of the cooling plate265 extends between a foot 219 of the bottom surface 262 of each arrayframe 254 and the tray 201. One or more walls 203 of the battery pack200 may surround the battery array 278.

The battery array 278 may be retained to the tray 201 of the batterypack 200 using one or more retention clips 205. In one embodiment,multiple individual retention clips 205 may be periodically spaced alonga length of the battery array 278 to retain the battery array 278 to thetray 201. The retention clips 205 are mounted to the tray 201, and inone embodiment are welded to the tray 201 as indicated by weld bead 207.Other mounting methodologies are also contemplated.

Each retention clip 205 may include a base 209 and a clip arm 211 thatextends from an end 213 of the base 209 opposite from an end 215 that isreceived against the tray 201. The clip arm 211 may include an undulatedshaped body. In one embodiment, the clip arms 211 include an extension217 that engages the foot 219 of the bottom surface 262 of each arrayframe 254 to retain the battery array 278 to the tray 201. When receivedagainst the feet 219, the retention clips 205 arrest movement of thebattery array 278 in the Z direction and at least partially in the X andY directions. Therefore, the battery array 278 can be retained to thetray 201 without using threaded fasteners or the like.

Referring to FIG. 9, which is a blown-up view of encircled area AR2 ofFIG. 8, the exemplary retention clip 205 is flexible between aninstalled position IP (i.e., a first position) and an installationposition IP′ (i.e., a second position, shown in phantom). In oneembodiment, the extension 217 of the clip arm 211 is received against asloped portion 221 of the foot 219 when the retention clip 205 ispositioned in the installed position IP, and the clip arm 211 isdisplaced from the foot 219 of the array frame 254 when the retentionclip 205 is positioned in the installation position IP′.

The retention clip 205 may be flexed in a first direction D1 to positionit in the installation position IP′, and may be flexed in a seconddirection D2 to return the retention clip 205 back to the installedposition IP. In one embodiment, the retention clip 205 is biased in thedirection D2, or toward the installed position IP. Therefore, duringinstallation of the battery array 278, the retention clip 205 is firstmoved to the installation position IP′ by applying a force in the firstdirection D1. Once the battery array 278 is in a desired position on thetray 201, the retention clip 205 may be returned to the installedposition IP to retain the battery array 278 in place.

One non-limiting installation method is schematically illustrated inFIGS. 10A, 10B and 10C. In this method, the battery array 278 createsthe force necessary to displace the retention clip 205. First, thebattery array 278 is lowered into position relative to the retentionclip 205 (see FIG. 10A). Next, one or more feet 219 of the array frames254 of the battery array 278 may engage the retention clip 205 and causeit to flex from the installed position IP to the installation positionIP′ (see FIG. 10B). The feet 219 are moved until they make contact withthe cold plate 265. Once the battery array 278 is properly positioned,the retention clip 205 can automatically return toward the installedposition IP.

In the embodiment illustrated in FIGS. 10A-10C, the retention clip 205is a flexible construct and the feet 219 of the array frames 254 arerigid constructs. However, an opposite configuration is alsocontemplated in which the retention clip is rigid and the feet of thearray frames are flexible.

For example, as shown in the additional embodiment of FIG. 10D, flexiblefeet 219A may extend from one or more array frames 254A of a batteryarray 278A. In one embodiment, the feet 219A extend from a bottomsurface 262A of each array frame 254A toward a tray 201A. The feet 219Amay include ledges 227A that protrude outwardly from the feet 219A. Arigid retention clip 205A is mounted to the tray 201A and may include abase 209A and a clip arm 211A that extends upwardly from the base 209A.The clip arm 211A may include multiple openings 223A for receiving theledges 227A of the feet 219A of the array frames 254A to secure thearray frames 254A to the tray 201A.

During a non-limiting mounting procedure, the feet 219A may flex in afirst direction D1 in response to contacting the clip arm 211A of therigid retention clip 205A. Once the feet 219A have flexed far enough inthe direction D1 that the ledges 227A are able to avoid interferencewith the clip arm 211A, the feet 219A may flex in a second direction D2that is opposite of the first direction D1 to position the ledges 227Ainto the openings 223A and retain the array frame 254A, and thus thebattery array 278A, to the tray 201A.

In yet another embodiment, rather than using multiple individualretention clips, a single retention clip assembly may be used to retainmultiple battery arrays 278 to the tray 201. One such retention clipassembly 205A is illustrated in FIGS. 11 and 12. The retention clipassembly 205A includes a base 209A and multiple clip arms 211A thatextend upwardly from each side of the base 209A. The clip arms 211A mayeach engage feet 219A of array frames 254A of adjacent battery array278A, 278B (see FIG. 12).

In another embodiment, a stop block 235 may be received into a recess299 of the retention clip assembly 205A. The stop block 235 may bereceived against the base 209A between the clip arms 211A of theretention clip assembly 205A. Alternatively, the stop block 235elevation may be controlled by engaging the tops of the retention clips205, or the tops of the feet 219. The stop block 235 can be positionedto arrest loads applied in the X direction. In one embodiment, the stopblock 235 is made of either plastic or rubber materials. However, othermaterials are also contemplated within the scope of this disclosure.

The various battery array design features described above andillustrated with respect to FIGS. 2-12 are intended as non-limitingembodiments only. Any feature shown in these figures may be combinedwith any other feature to create array frames, battery arrays and/orbattery packs having unique features.

Although the different non-limiting embodiments are illustrated ashaving specific components or steps, the embodiments of this disclosureare not limited to those particular combinations. It is possible to usesome of the components or features from any of the non-limitingembodiments in combination with features or components from any of theother non-limiting embodiments.

It should be understood that like reference numerals identifycorresponding or similar elements throughout the several drawings. Itshould be understood that although a particular component arrangement isdisclosed and illustrated in these exemplary embodiments, otherarrangements could also benefit from the teachings of this disclosure.

The foregoing description shall be interpreted as illustrative and notin any limiting sense. A worker of ordinary skill in the art wouldunderstand that certain modifications could come within the scope ofthis disclosure. For these reasons, the following claims should bestudied to determine the true scope and content of this disclosure.

What is claimed is:
 1. A battery array, comprising: a first array framethat includes a thermal fin; a second array frame connected to saidfirst array frame, said second array frame including a relief notch thatreceives a portion of said thermal fin.
 2. The battery array as recitedin claim 1, wherein said relief notch is formed in a bottom surface ofsaid second array frame.
 3. The battery array as recited in claim 1,wherein said thermal fin includes a body positioned within a frame bodyof said first array frame and a leg that extends outside of said framebody.
 4. The battery array as recited in claim 3, wherein said legincludes a bent end portion that is received within said relief notch.5. The battery array as recited in claim 3, wherein said thermal fin issegmented into a plurality of leg portions by notches or cuts.
 6. Thebattery array as recited in claim 3, wherein said thermal fin isflexible between a first position in which said leg is spaced fartherfrom a bottom surface of said frame body and a second position in whichsaid leg is closer to said bottom surface of said frame body.
 7. Thebattery array as recited in claim 6, wherein said leg extends at anobtuse angle relative to said body of said thermal fin in said firstposition.
 8. The battery array as recited in claim 6, wherein said legis perpendicular to said body of said thermal fin in said secondposition.
 9. The battery array as recited in claim 1, wherein a leg ofsaid thermal fin is sandwiched between bottom surfaces of said firstarray frame and said second array frame and a cooling plate.
 10. Thebattery array as recited in claim 3, wherein one end of said body isreceived in a groove of a top surface of said frame body, an oppositeend extends through a passage of a bottom surface of said frame body,and said leg extends beneath said bottom surface.
 11. The battery arrayas recited in claim 1, wherein said first array frame and said secondarray frame are snapped together.
 12. The battery array as recited inclaim 1, wherein one of said first array frame and said second arrayframe includes a flexible snap arm and the other of said first arrayframe and said second array frame includes a rigid snap arm, and saidflexible snap arm engages said rigid snap arm to connect said firstarray frame to said second array frame.
 13. The battery array as recitedin claim 1, wherein each of said first array frame and said second arrayframe include a plurality of retention features that snap together toconnect said first array frame to said second array frame.
 14. Thebattery array as recited in claim 1, wherein said first array frame is aunitary plastic structure.
 15. The battery array as recited in claim 14,wherein said thermal fin is molded into said unitary plastic structure.16. The battery array as recited in claim 14, wherein said thermal finis inserted into a groove formed in said unitary plastic structure. 17.The battery array as recited in claim 1, wherein each of said firstarray frame and said second array frame houses two battery cells. 18.The battery array as recited in claim 1, wherein each of said firstarray frame and said second array frame includes a recessed groove. 19.The battery array as recited in claim 18, comprising a tension strapseated within said recessed grooves.
 20. A battery array, comprising: afirst array frame including a frame body and a thermal fin, said thermalfin including a body received in said frame body and a leg that extendsoutside said frame body; a second array frame snapped into said firstarray frame such that said first array frame and said second array frameare abutting; and said second array frame includes a relief notch thatreceives a portion of said leg.